The motor vehicle industry, particularly the passenger car and van portions of the industry, are increasingly relying on flush glass window mounting for improving the appearance of motor vehicles and reducing the aerodynamic drag of the vehicles to make them more fuel efficient. A flush glass seal mounts to a door or window opening of a motor vehicle to engage three sides of a movable window glass. The fourth side of the window glass that remains within the door or body of the vehicle is sealed by a separate belt-line seal usually mounted thereon. Separate belt-line seals leave gaps where the window seal and the belt-line seal meet which are a source of leaks and permit excessive window rattle and allow road noise to penetrate the interior of the vehicle.
Thermosetting materials such as ethylene-propylene-diene-monomer rubber (EPDM) have been used extensively for vehicle window seals and belt-line seals. Some complex seals have included portions formed from other materials such as thermoplastic materials, but EPDM has usually been a major portion of these seals. To improve the appearance of motor vehicles, the industry demands window seals that are colored to enhance the appearance of the vehicle, usually by matching the body color. Obtaining a color on EPDM has been less than satisfactory in the past, whereas thermoplastics are readily colored. Although EPDM is cost effective (inexpensive) as a material, the total cost of making and installing an EPDM seal on a motor vehicle is high. The seal must not only be formed at the radii of the glass by cutting, mitering or welding molded pieces, but it must also be arched in the vertical direction to coincide with the curved glass and rounded sides of the vehicle. To accomplish this with EPDM, a metal support internal to the EPDM is added, usually as the EPDM seal is extruded. Massive and expensive roll forming machinery and tooling, and stretch bending equipment and tooling are required to form the extruded seal to the desired configuration in three dimensions. Thus, the total cost, that is the cost of the seal and the capital cost of equipment needed to form it, is high.
U.S. Pat. No. 5,343,609 describes improved vehicle door or window channel seals that overcome the disadvantages of EPDM seals. The seals have two members, a substantially rigid first carrier member thermally formed from a hard, rigid or semi-rigid plastic and a soft plastic, and a second sealing member made from resilient material, preferably rubber. The first sealing member comprises a dual durometer, thermoplastic elastomer (TPE) which attaches to the vehicle body and can be color matched to an automobile. The first member is thermally formed by extrusion or molding in one piece and immediately conformed to the contour of the vehicle opening. Thus molded joint lines and the need for cutting, mitering or welding of the carrier member to fit the corners are avoided. The second sealing member can be formed by extrusion of a one piece, relatively flat, rubber insert which can be readily provided with a sliding surface, such as a slip coating or flocking. A separate belt-line seal is required when this two-piece seal is used as a door window channel seal.
It is an object of this invention to provide a resilient sealing insert for a TPE flush glass window channel seal having a channel sealing portion integral with a belt-line extension.
It is an object of this invention to provide a resilient insert for a flush glass window seal, the resilient insert having a tearable line of weakness for separating the insert into a window run channel portion and an integral belt-line extension.
It is an object of this invention to provide a method of forming a one-piece window run channel insert having an integral belt-line extension.